Portable furnace for thawing earth and the like



July 2, 1963 c. w. SHARKEY 3, 7

PORTABLE FURNACE FOR THAWING EARTH AND THE LIKE Filed Sept. 14, 1961 2Sheets-Sheet 1 64- x02. I04- /4 70 110 I u H2 U A Z0 8 72 I18 66 a 58 HK1 /6 l6 56 F I G. l.

INVENTOR. CHESTER 14/. SHA/PAZ'Y BY v July 2, 1963 c. w. SHARKEYPORTABLE FURNACE FOR THAWING EARTH AND THE LIKE I Filed Sept. 14, 1961 2Sheets-Sheet 2 #6 INVENTOR.

PIC-3.7.

ATTU/F/VEYS 3,095,870 PORTABLE FURNACE FOR THAWING EARTH AND THE LIKEChester W. Sharkey, 2025 Anderson Road, Duluth, Minn. Filed Sept. 14,1961, Ser. No. 1ss,029 2 Claims. (Cl. 126271.2)

The invention relates broadly to an improvement in heating devices andmore particularly to a portable furnace unit for thawing frozen earthwhich facilitates removal of the same.

-In northern climes where the earth may become frozen to a considerabledepth during winter months, it is necessary to first thaw the earthbefore a. digging operation. Where earth is removed for a grave, acesspool or a drain field, as examples, the frozen ground must be thawedto allow economical removal of the same. In digging up portions ofroadways, as a further example, the frozen earth must first be thawed.Sand and brick may require heating before it is usable.

It is an object of this invention to provide a portable furnace unitwhich may be easily moved to a desired spot and operated so as to heatand thaw areas of earth, sand, brick and the like. It is a furtherobject to provide a heater which may not only be used to thaw earth andthe like but which may be used to warm an interior of an enclosedstructure. 7

It is also an object to provide a furnace unit having an enclosed bodymember forming a heat chamber open at the bottom and within which ismounted a multiplicity of closed heat conduits, the body memberconfining and directing heat from the conduits to an area of a surfaceon which the unit rests substantially defined by the periphery of thebody member. It is an additional object to provide a portable furnacewith which there is no exposed flame directed onto the material to beheated.

It is a further object to provide a furnace unit which will operatewithout the need for an external electrical source of power.

It will not be here attempted to set forth and indicate all of thevarious objects and advantages incident to the invention, but otherobjects and advantages will be referred to in or else will becomeapparent from that which follows.

The invention will appear more clearly from the following detaileddescription when taken in connection with the accompanying drawingsshowing by way of example a preferred embodiment of the inventive ideawherein like numerals refer to like parts throughout.

In the drawings forming part of this application:

FIGURE 1 is a perspective view of the furnace in partially raisedposition with a portion of the power plant housing being broken away.

FIGURE 2 is a sectional View on the line 2-2 of FIGURE 4.

FIGURE 3 is a sectional view on the line 3-3 of FIGURE 4.

FIGURE 4 is a top plan View of the heater.

FIGURE 5 is a plan view of the underside of the furnace.

FIGURE 6 is an enlarged perspective view of the winch used to raise andlower the body member.

FIGURE 7 is a detailed fragmentary sectional view of the top of the mainchamber and the connection of the lift cable with the multiple heatconduit member.

Referring to the drawings in detail, the furnace A includes the mainbody member 8 which is also the primary heat chamber 10 formed of theinsulated double side walls 12 and 14, the insulated double front andrear end walls 16 and 18, respectively, and the insulated double topwall 20. Insulation is indicated by the numeral 21.

Patented July 2, 1963 Further provided is the multiple heat conduitmember 22 which is mounted within the chamber 10. The multiple conduitmember 22 includes the longitudinally disposed outer heat conduitportions 24 and 26 which are connected at the rear ends thereof to thetransverse rear heat conduit portion 28. The rear conduit portion 28 isconnected centrally to the rear end of the central longitudinal conduitportion 30. The central conduit portion 30 is closed off at its forwardend with the cap 32. The front ends of the longitudinal outer conduitportions 24 and 26 connect with the transverse front conduit .portion34.

Mounted within the conduit portion 34 is the transverse fire wall 36,and extending into and forming a part of the transverse conduit portion34 is the fire box 38.

The multiple heat conduit member 22 is mounted within the primary heatchamber 10 by means of the horizontal transverse support 40 which issecured at one end to the side wall 12 and at the other end to the sidewall 14 with the rear transverse conduit portion 28 connected to thesupport 40 by means of the ears 42 connected to the portion 28 and thesupport 40 as at 44 and 46. The heat conduit member 22 is furthermounted within the chamber 10 by means of the transverse horizontalbracket 48 secured to the front end wall 16 and the outer surface of thefront end of the fire box 38.

The front wall 16 has formed therein the opening 50 through which aportion of the casing 52, oil burner 54 extends into the fire box 38.The oil burner 54- is mounted in the housing 56 connected to the frontwall 16 at the opening 50. The oil burner '54 receives a supply of oilfrom the oil line 58 leading from the oil supply tank 60 mountedadjacent the rear end of the top wall 20.

The oil burner 54 may be operated by an external source of electricalpower where the same is closely available to the point of operation ofthe heater A; however where the heater A is used where power is notavailable there is provided a gasolene driven conventional powergenerating plant indicated in block outline as 62 which is mounted onthe top wall 20 within the housing 64. Power is delivered to the oilburner 54 from the generating plant 62 by means of a conventional powerline connection 66.

Leading from the upper front end of the central heat conduit portion 30is the outlet stack 68.

Further provided is the yoke 70 including the spacd vertical leg members72 and 74 connected at the upper ends thereof by the horizontal crossbar 76. The vertical members 72 and '74 of the yoke 70 are positionedalongside the body member 8. The vertical leg member 72 is slidablymounted on the side wall 14 by means of the pair of upper brackets 78and the pair of lower brackets 80. The remaining leg member 74 of theyoke 70 is slidably mounted on the side wall 12 by means of the upperbrackets 82 and the pair of lower brackets 84.

The body member 8 is raised and lowered relative to the yoke 70 by meansof the winch 86 mounted on the cross bar 76 of the yoke 70. The winch 86includes the drum 88 mounted on the shaft 90 supported by the spacedupright supports 92 and 94 secured to the base 95. Also mounted on theshaft 90 between the support 94 and the additional vertical support 96is the gear 98 rotated by the worm gear 100 by means of the crank handle102. The worm gear .100 is rotatably mounted on the upright support 96.A cable 104 is wound on the drum 88 and extends over the pulley 106rotatably mounted on the supports 108 and 110 secured to the top of thecross bar 76 centrally thereof. The cable passes downwardly from thepulley 106 through a hole 112 formed in the top wall 20 with the end ofthe cable secured to the brackets 114 and 116 of the top wall 118 of thecentral conduit portion 30. With the conduit unit 22 secured to the i 3body 8, the two are raised as a unit by means of the cable 104 operatedby the crank handle 102.

The top walls of the heat conduit member 22 are spaced from theunderside of the top wall 20 of the chamber 10, FIGURE 7, by means ofthe brackets 11-4 and 116 whereby heat may circulate between the top ofthe conduit unit 22 and the wall 20.

The numeral 118 designates a vent plate which covers an opening 120formed in the top wall 20 and which is removable. When it is desired todirect heat upon a surface, for example, the plate 118 is maintained inposition upon the top 20 to thereby close oh the opening 120. However,if it is desired to heat the interior of a structure, the furnace A maybe placed therein and operated with the plate 118 removed and the body 8raised off the ground thereby assuring maximum dispersal of heat fromthe unit into the structure.

Rotatably mounted on the lower end of each of the leg members 72 and 74of the yoke 70 is a wheel 122,

and connected to the lower bracket 80 is the half wishbone portion 124.A similar half wishbone portion 126 is connected to the lower bracket84. The wishbone portions 124 and 126 are joined at the outer free endsto a trailer hitch member, not shown, whereby the unit A may be towed toa point where it is to be used.

In using the furnace A, the same, for example, may be used to thawfrozen ground for the purpose of digging a grave. The power plant 62 isstarted, and with power supplied to the oil burner 54 the burner isstarted. Heat from the burner 54 strikes the fire wall 36 and isdispersed laterally :to longitudinal conduits 24 and 26 where it travelsthrough both conduits to the rear transverse conduit 28 where it entersthe central conduit 30 and is vented from the central conduit out thestack 68. The heat emanating from the conduits 24, 26, 28 and 34 floodsthe entire interior of the chamber 10. The body 8 is lowered by means ofthe cable 104 to the ground so that the entire lower edge of the body isin contact with the ground. As a result, the heat in the chamber ismain- T rained therein and subjected in concentration to an area ofground defined by the perimeter of the lower edge of the chamber 10.Actually the ground will be thawed to an extent beyond an area definedby the body 8, but

the concentration of heat is within the body 8 upon the:

ber 10 is effected by the thermocoupie 128 extending into the chamber'10 and connected to a conventional thermostat, not shown, whichoperates the burner 54. The burner may be of the gas type with a supplyof bottled gas.

When the ground is sufficiently thawed,the body 3 is raised by means ofthe cable 104, and the unit A may then be towed away.

The invention is not to be understood as restricted to the details setforth since these may be modified within the scope of the appendedclaims without departing from the spirit and scope of the invention.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent, is:

1. In a portable furnace for heating earth and the like, a body memberhaving a top, side walls, end walls and open at the bottom, a pair ofspaced longitudinally extending outer heat conduits positioned withinsaid body member, a rear transverse heat conduit connecting the .rearends of said outer longitudinal heat conduits, a

front transverse heat conduit connecting the front ends of said outerlongitudinal heat conduits, a central heat conduit connected to saidrear conduit and extending between said pair of longitudinal conduits, avent pipe extending from said central heat conduit, means for supplyingheat to said front transverse heat conduit for travel throughout theremaining heat conduits and out said vent References Cited in the fileof this patent UNITED STATES PATENTS 574,653 Barber Ian. 5, 18971,062,655 Macleod May 27, 1913 1,585,662 Gardner et a1. May 25, 19262,091,980 Hamlink Sept. 17, 1937 2,439,038 Cartier Apr. 6, 1948 FOREIGNPATENTS I 152,350 Sweden. Nov. 15, 1955 626,687 Canada Sept. 5, 1961

1. IN A PORTABLE FURNACE FOR HEATING EARTH AND THE LIKE, A BODY MEMBERHAVING A TOP, SIDE WALLS, END WALLS AND OPEN AT THE BOTTOM, A PAIR OFSPACED LONGITUDINALLY EXTENDING OUTER HEAT CONDUITS POSITIONED WITHINSAID BODY MEMBER, A REAR TRANSVERSE HEAT CONDUIT CONNECTING THE REARENDS OF SAID OUTER LONGITUDINAL HEAT CONDUITS, A FRONT TRANSVERSE HEATCONDUIT CONNECTING THE FRONT ENDS OF SAID OUTER LONGITUDINAL HEATCONDUITS, A CENTRAL HEAT CONDUIT CONNECTED TO SAID REAR CONDUIT ANDEXTENDING BETWEEN SAID PAIR OF LONGITUDINAL CONDUITS, A VENT PIPEEXTENDING FROM SAID CENTRAL HEAT CONDUIT, MEANS FOR SUPPLYING HEAT TOSAID FRONT TRANSVERSE HEAT CONDUIT FOR TRAVEL THROUGHOUT THE REMAININGHEAT CONDUITS AND OUT SAID VENT